The invention relates to a fan system for a cooling system of an internal combustion engine having an electric machine and an impeller wheel, wherein the electric machine comprises a pole housing which is rotatably mounted by means of a bearing, and wherein the impeller wheel is coupled to the pole housing of the electric machine.
Fan systems having an electric machine which is embodied as an external rotor are known. In order to attach an impeller wheel to a pole housing of the electric machine, what is referred to as a joining mandrel usually has to be inserted between an axle of the pole housing and the fan during assembly of the electric machine and is removed again after the fan is screwed to the pole housing. Joining play between the joining mandrel and the axle or between the joining mandrel and the fan is necessary for this. This joining play has to be taken into account in addition to the component tolerances of the fan system, and therefore at the same time increases the radial play between the fan and the axle.